Silo.



A G. HAGUE.

APwcm on mu; 050.11, I914.

Patented June 22, 1915.

2 SHEET$-SHEET 2.

UNITED STATES PATENT OFFICE.

ALFRED G. HAGUE, OF DES MOINES, IOW'A, ASSIGNOR T0 0'. 1R. SAVAGE, OF DES MOINES, IOWA.

Specification of Letters Patent.

Patented June 22, 1915..

Application filed December 17. 1914. Serial No. ETTJBB.

To all whom it may concern:

Be it known that I, ALFRED llAGUE, a citizen of the United States, residing at Des Moines, in the county of Polk and State of Iowa, have invented a new and useful Silo, of which the following is a specification.

My invention relates to that class of circular structures in which are included silos. water tanks, and the like. These are usuallymade of circular form of a number 0:? upright staves or blocks, and are ordinarily held together by hoops or hands running around the outside of the structure. In structures of this kind heretofore in some instances the upright stoves or blocks have been connected together by tongues and grooves, or by cement, or mortar, or other ways. These upright staves or blocks are in some instances made of material such as concrete.

In the construction of silos and other buildings of concrete staves or blocks held together by steel hoops or bands, the stoves as well as the hoops or bands will contract and expand to a certain extent, due to difi'en ences in temperature. When a means of any kind is employed tending to connect together the side edges of the adjacent stoves or lllOCllS, then there are always one. or more of these connections that are Weaker than the others, hence when an unusual degree of ere pansion takes place, a number of the stoves or hloclis Will adhere together, and one or more of the joints hetvvern the upright ed 3 of the staves or hloclis ill separate. lhose that hawthe weakest. connection are the ones that will thus separate. The result of this is that a large majority of the joints will re main air-tight and Water-proof, While one or more of the weaker connections will separate appreciably, and permit a leakage of: air. Fu thermore, it has been customary heretofore in structures such as silos made of mate ial such as concrete, to apply to the F I L interior of the structure after it is finished lmtvveen the upright staies separate. 'lhut 1+5- due to the tact thul While this layer or writing of cementitious material has a very slight degree of llexihility, it will crack and separate if there is an a ppreciu hle movement of the sta ves or hlocks away from each other at a joint.

My object is to provide a structure of this class in which the upright staves or blocks forming the structure are not connected together at their 'icent, edges, so that each vertical s no or cl; throughout the entire structure is in" 1w. to move relative to its adjoinim, we r block as every other, so that when on u ual degree of expansion takes place. this movement of the stavcs or hloclas will l e uhsoiutoly uniform. In other Words. it in ohuct to provide a structure. of the character d scrihed in which each of the vertical meeting: edges between all the staves or hloclrs oi the silo will have exactly the same treedi'in'i of movement- Whereliy this movement. when it takes place, Will be evenly distributed lhri'iughout the entire structure, so that when the thin layer or coating of cementitious material is applied to the in-- terior of the structure and even extreme ex pansion takes plat: the movement at each of the \ertical joints between the staves or blocks will he so uniform and so slight that the layer of cemontitious material will yield or bend without actually cracking and sepafratin I More specifically it is my object to provide alternately arranged rows of upright stoves, ear-h alternate row heinu of different structure. so that the encircling hoops or bands will touch hoth corn rs of one row of lip-- ris'hl. stairs er hi 7 While the miliacent row of upright sto es oi l lut'lis will stand Wholly spaced apart from. the encircling hoops or hands.

Further in this connection it is my object to provide the upright rows of staves or blocks that do not touch the encircling hoops or hands with edges so shaped that they will have a somewhat Wedge-lil e effect. That is to say, when a great pressure is exerted upon the interior of the silo, the rows of stoves or blocks that touch the encircling hoops or bands will he held stationary against radial movement. but the rows of slaves or blocks that do not touch the encircling hoops or hands may more to a limited extent outwardly toward the hoops or hands, the wedge-like shape of the side edges of said blocks heing so arranged that when this internal pressure is applied in the mannor just described, the tendency will be for the inner corners of the wedge staves 0r blocks to press more firmly against the adjacent inner corners of the adjoining blocks, and thereby n'iaintain the airtight connection between the said edges.

in. this connection it my object further to so construct the silo that a movement of the rows of stavcs or blocks relative to each other will be so evenly distributed throughout the structure that it will be minimized to such an extent as to prevent the cracking of the layer or coating of cementitious material.

A further object is to provide a structure whereby when the entire silo contracts, as it will do on an extremely cold day, the encircling hoops or bands will become decreased in diameter, and there will, therefore, be a movement of the entire structure toward the center of the structure. When this occurs my improved structure will permit such m vement, and at the. same time evenly distribute this movement throughout all of the meeting edges of all the rows of upright staves or blocks, so that the layer or coating of e mentitious material will not be cracked or broken on account of such movement My invention consists in the construction of the side edges of the upright rowsof staves or bloclis, and in the combination with said locks of the encircling hoops or bands arranged to engage both edges of one row of blocks, and to stand wholly spaced apart from the adjoining row of upright staves or blocks. whereby the obj cts contemplated are attained, as hereinafter more fully set forth, pointed out in my claims and illustrated in the accompanying drawinns, in which:

Figure I shows a side elevation of a silo embodying: my invention. Fig. 9 shows an enlarged, detail. horizontal. sectional view through a part of a silo wall embodying my invention. with a portion of the encircling hoop or band surrounding it and Fig. 3 shows a horizontal, sectional view of a silo or similar structure embodying my inven tion.

Referring to the accompanying drawings, it will be seen that the silo is constructed of two sets of upright staves or blocks, one set being designated generally by the reference numeral 10, and the other by the reference numeral 11. In Fig. 3 of the drawings l have shown the staves or blocks it) to be of somewhat greater width than the staves or blocks 11. This, however, is not essential. The side edges of the strives or blocks 10 are con vex, preferably on a curve whose diameter is the same as the thickness of the stave or block, and whose center is midway between the inner and outer sin-farms of the tave or block. the sta es or blocks it are owned with the r with; edges eonezu. e. The circle on which each concave edge is constructed is preferably of a diameter equal to the thickness of the stave or block, the center of the circle being on a line, which, if projected beyond the stave or block, would be midway bet een the outer and inner surfaces of the stave or block. The outer and inner corners of each side edge are preferably cut away at l). The encircling hoops or bands indicated by the reference numeral 13, are of the ordinary kind commonly employed in the construction of silos of various kinds, and preferably made of steel, and round in crosssection. They may be adjusted to fit the silo by any of the ordinary devices now in common use, such, for instance, as the kind illustrated in Fig. 3 and indicated by the reference numeral 14.

In the erection of the silo I preferably first provide a solid base 15. Then the staves or blocks, which are made in short lengths as illustrated in Fig. 1, are placed in a circle upon the base, and are laid up without mortar or cement at the joints. 1' first provide one vertical row of relatively wide staves or blocks 10, and adjacent to it a vertical row of relatively narrow staves or blocks 11, and so on throughout the entire silo. I also preferably break the joints at the ends of the stav es or blocks in the manner indicated in Fig. 1, that is to say, first a. wide stave or block 10 and a narrow one 11 are placed side by side, and then another vertical row consisting of a wide and a narrow stave or block is placed in position, with the ends thereof in a different horizontal plane from the first vertical row of wide and narrow staves or blocks before mentioned. In order to do this, I preferably employ for the bottom and top horizontal rows, :1 number of slaves or blocks of about half the length of the main staves or blocks of the silo. The encircling hoops or hands are preferably placed around the structure at each of the horizontally arranged rows at the ends of the staves or blocks, so that each stave or block is engaged by a hoop or band at its center and both ends. This, however, is not essential to the successful use of my invention.

After the silo is erected in the manner described, I preferably provide a layer or coating of cementitious material 16 to the inner surface of the silo, which is preferably applied w ith a brush and is therefore relatively thin. This layer or coating has only a very slight degree of flexibility and will crack if there is any material movement of the staves or blocks to which it is applied, in a (liIOt'tiOll to pull them apart, at a place where the vertical joints occur, but if the slight movement which is occasioned by the contraction and expansion of the silo is ((lltflllZfill and made uniform at every one of the l "nits throughout the entire silo, then this movement of the staves or blocks relative to each other is so slight that the layer or coating of cementitious material will not be broken.

In this connection it should be explained that the expansion and contraction of the silo hoops or bands is in some instances and at some places difi'erent in amount from the extremely cold weather it sometimes occurs that there will be strong sun light on one side of the silo, whereas-the other side will be in the shade and subjected perhaps to a temperature below zero, so that the portions of the hoops or bands that are exposed to the sun light will be expanded and the other parts contracted? and this contraction and expansion of different parts of the steel encircling hoops or bands may be different from the corresponding construction and expansion of the staves or blocks.

By means of my improvement, I hare found that under allof the conditions to which silos of this kind are ordinarily subjected, in localities having extremes of temperature, such, for instance, as ordinarily occurs in the State of Iowa, the contraction and expansion occasioned thereby, either of the hoops or bands, or of the staves or blocks, will not be suflicient in amount at any one of the vertical joints to break or crack the layer or coating of cementitious water-proofing material on the interior of the silo, and that the *silo will remain airtight and water-proof as required to preserve ensilage.

In practical use, and assuming that the hoops or hands, or parts of them, expand on account of heat or great internal pressure, then the staves or blocks 11 which are in engagement with the hoops or bands will move outwardly to a slight, extent, but the joints between the vertical row-s will not be broken, because the staves or blocks 11 may separate at their side edges near their outer surfaces to a slight extent from the adjacent portions of the staves or blocks 10, but the inner edges thereof at the point marked A in Fig. 2 will be pressed firmlyagainst the adjacent portion of the stave or block at the point marked B. This occurs because the inner half of the stave or block 11 is substantially wedge shaped, and the internal pressure of the material in the silo will force the vertical stave or block outwardly, thus maintaining a tight joint between the parts A and 13, although as before stated the outer edges may separate slightly. In a silo of ordinary size, made in substantially the proportions illustrated in Fig. 1, the maximum movement of this kind to which a silo is ever subjected, is not su'fiicient to crack or break the layer or coating 16 of cementitious material.

Assuming furthermore, that the hoops or hands contract either throughout the entire circle or some part of it, then there will be an inward pressure upon the staves or blocks 10, but no inward pressure directly applied to the staves or blocks 11, therefore the tendency will be to force-the parts B of the staves or blocks 10 inwardly firmly into engagement with the parts A of the staves or blocks 11. This will also tend to force these-parts together instead of apart, and a slight amount of this movement when distributed throughout all. of the staves or blocks of a silo will not be sufiicient to crack or break the layer or coating of cementitious material.

By having the vertical joints between the staves or blocks made on curved lines, as illustrated, an advantage is gained in that staves or blocks may all be made on the same curve, and used to construct silos, water tanks and other buildings of any desired diameter, there being no necessity of shaping these staves or "blocks for any particular diameter for a silo or other building. Furthermore, the curvature of the blocks at the points marked A and B is advantageous because during outward movement of the staves at any point or throughout the entire silo, the points A and B will in effect become pivotal points, which will be held firmly together even though the vertical joints near the outer surface of the silo should slightly open up.

By means of my improvement the inward and outward movement of the staves orblocks which necessarily occurs on account of the contraction and expansion incident to differences in temperature, isequalized and compensated for in such a manner that a practically inappreciable movement occurs at every vertical joint. Hence with my improvement it never occurs that at some one vertical joint there is an excessive separating movement of the staves or blocks sufiicient in amount to crack the layer or coating of cementitious material, whereas with the ordinary form of silos or buildings of this kind when the staves or blocks are held together by cement or mortar, or by tongue and groove, or-in any other way, there is always one vertical joint weaker than the others, and all of the tion and expansion will fall on one or more of the vertical joints, and under these circumstances it may become so excessive as to crack the layer or coating of cementitious material. Furthermore, even though the separating movement occasioned by contrac- I vertical rows of staves or blocks were not held together in any of the usual ways, it is obvious that if the hoops or bands firmly engage every vertical row of staves .or blocks, then this frictional engagement will tend to hold them together, so that when the hoops or bands are subjected to unequal expansion, as herein indicated, then parts of them will tend to move circumferentially around the silo, and on account of the frictional engagement between every stave and the hoops or hands, this frictional engagement will obviously be less on some one particular row of staves or blocks, and Where this pressure or frictional engagement is the weakest the joint adjacent thereto will separate to an extent great ehongh to cause a crack in the layer or coating of cemcntitious material, and the adjacent vertical joints of th* staves or blocks that are firmly in frictional engagement with the hoops or bands will all stick together, and have no appreciable outward or separating movement. llut by providing a structure in which the adjacent vertical rows of staves or blocks are not connected in any way, and are also arranged with one vertical row of staves or blocks engaged by the hoops or bands and the adjoining ones spaced apart slightly from the hoops or bands, I accomplish the result of providing equal movement at every vertical joint with the effect of distributing this relatively sli ht movement over so many of the-vertical joints as to avoid the possibility of cracking the layer or coating of cenientitious material at any point throughout the entire silo.

The outer corners of the staves 11 are cut away or beveled at 12to avoid any possibility of the corners of the staves 11 coming in contact with therhoops as such contact would prevent the structure from accomi lii-.hing the results contemplated. I have found that if any solid body is inserted against the outer surfaces of the staves 11 and also contacts with the hoops then, during contraction and expansion of the silo, he joints will separate to such an extent as to crack the coating or layer 16. In a structure of this class it is more convenient and economical to make all of the staves of the same thickness and when this is done the beveled corners 12 are the best means I have devised for preventing the concaved edged staves from contacting with the hoops.

I claim as my invention:

1. In a structure of the class described, the combination of a series of staves arranged in substantially circular form, an encircling hoop on the exterior thereof, some of said staves having two convex edges and the others having two concave edges to 00- act with the said convex edges and being arranged alternately in the structure, said staves being provided with means whereby the convex edged staves only engage the hoop and the outer faces of the concave edged staves are not engaged either directly or indirectly by the hoop, whereby when the structure expands or contracts, due to internal pressure or to changes in temperature, the inner corners of the meeting edges of the staves will remain firmly in contact even though the outer corners of the meeting edges should slightly separate.

2. In a structure of the class described, the combination of a series of staves each being substantially the same thickness as the I others and being arranged in substantially circular form in the structure, an encircling hoop on the exterior thereof, some of the staves having two convex edges and the others having two concave edges to co-act 'with the said convex edges and being arranged alternately in the structure, the outer- 

